Spark plug



Patented Aug. 18, 1925,

- UNITE-D :ST1-M755 Vcsr-rmx rana e Application led October 7;@1321'.nSeralrfNQ150.55975.

To @ZZ whom t may concern:

Be it known that we, WILLIAM A. HUGKE and Lne A. SAUER, citizens of the United States, residing at Cincinnati, in the county of Hamilton and Sta-te of Ohio, have invented new and useful Improvements in Spark Plugs, of which the following is a specification. y

Our invention relates to spark plugs for the cylinders of internal combustion engines; in which the electrodes, being located directly in the combustion chamber, become coveredby the dust of the spent carbon accumulated on the electrodes which reduces and sometimes closes the space between them; and this deposit held together by the spent oil on the electrodes, frequently pro duces a short circuit preventing passage of the current.

Vhere the porcelain is exposed to the intense heat of the flame from the explosion, it not only becomes foul with carbon, but cracks and must be replaced by a new one.

Our improved spark plug is designed to remedy these difficulties by preventing the accumulation of carbon on the electrodes and porcelain surface and of oil on the elec trodes. rlhe construction and relation of parts are such that the electrode is located in an olf-set of the combustion chamber, the entrance to which i-s an enlargement containing an enlarged receiving electrode, the arrangement being such as to produce a strong outward sweep of the united gases tending to cleanse the .surfaces and prevent lodgment of any dust, etc.

Qur invention is illustrated in the accompanying drawings in which Figure l is an elevation of the spark plug, and

Fig 2 is a vertical axial section of the same.

Referring now to the drawings, A is the upper element of the metal casing of the spark plug, threaded on its lower end for engagement with the lower element B of the casing, and the lower end of B preferably made long, is threaded for engagement with the cylinder of an internal combustion engine, thru which the ground connection for the plug is made.

The lower electrode is a sphere a, secured to the upper element A, of the casing, by a suitably bent rod al.

The upper electrode c is suitably insulated from the casing by the usual porcelain C and is held securely in place by the gland nut a2.

The lower element B of the casing, is hollowed out to form a chamber b with rounded walls, adapted to prevent throwing the flame or the products of combustion upward toward the electrode c and the porcelain C. In furtherance of this aim, the member A is undercut at a3. The spherical electrode a is of such size and so placed a-s to prevent oil being thrown past it on to the upper side of a, and onto the electrode 0. Instant and certain formation of the spark is insured.

Any modification of the structure herein shown, that is within the scope of the claims ,hereinafter set forth, is within the spirit of our invention, and we do not limit ourselves to the preferred form shown, which is the best one known to us at this time.

We claim as our invention and desire to .secure by Letters Patent of the United States 1. A spark plug having in combination, a

casing formed of two elements: an enlarged combustion chamber within said casing, an opening from said chamber to a smaller chamber within which is the upper electrode; an insulating porcelain for said upper electrode with lower end above said opening; and an enlarged lower electrode fiXedly secured to said casing and .so placed within the connecting chambers that the ignition of the contained gases compels an outward flow over and around the lower electrode.

2. A spark plug comprising a casing within which is a lower enlarged combustion chamber and an upper connected smaller chamber, an electrode within said upper chamber and a spherical electrode iixedly secured to the casing substantially within said lower *chamber of such size and so placed as toshield said upper chamber from below. l

3. A spark plug having in combination, a casing formed of two elements, an enlarged combustion chamber within said casing, an opening from said chamber to a smaller chamber within which is the upper electrode, an insulating porcelain for said upper electrode with lower end above said opening, a lower electrode fiXedly secured to said casing and of such size and shape and so placed as to be adapted to shield said opening from below, and an elongated lower end on the lower of said casing elements.

electrode within the lower chamber xedly secured to the casing and so placed as to shield said opening from below. 10

In testimony whereof We have hereunto set our hands.

WILLIAM A. HUCKE. LEO A. SAUER. 

